Solar Advanced Oxidation Processes as disinfection tertiary treatments for real wastewater: Implications for water reclamation

摘要

The aim of this study was to assess the disinfection of a real secondary effluent from a municipal wastewater treatment plant using added H2 O2 (20 and 50 mg L~(-1)), TiO2 (100 mg L~(-1)) and photo-Fenton under natural solar radiation in compound parabolic collector photo-reactors. For this purpose, the naturally occurring Escherichia coli, spores of sulphite-reducing Clostridia (SRC), somatic coliphages (SOMCPH) and F-specific RNA bacteriophages (FRNA) were tested before and along the different solar treatments. Results for E. coli showed the different treatments efficiency rank: photo-Fenton pH 3 > H2O2 (20 mg L~(-1) )/solar > TiO2/solar > solar photo-inactivation. On the other hand, for viral indicators the ranking was: photo-Fenton pH 3 > TiO2/solar > H2O2 (20 mg L~(-1) )/solar > solar photo-inactivation. SRC was the most resistant indicator microorganism in all the evaluated processes. For the first time these solar processes have been evaluated for naturally occurring conventional indicators such as E coli and alternative indicators such as SOMCPH and FRNA as viral indicators or spores of SRC as protozoan indicators. Some of the tested solar photo-oxidation treatments have shown their capability to reduce E. coli concentrations to a suitable level for water reuse (according to different reclaimed water guidelines) within affordable treatment times.